Straightedge instrument



1927. Aprll 26, G. LEE

STRAIGHTEDGE INSTRUMENT Filed Nov. 5, 1923 F'atented Apr. 26, E923 GILBERT LEE, OF RGOKFORID, ILLINOIS.

STRAIGHTEDGE INSTRUMENT.

Application filed November This invention relates in general to geometrical instruments, and has more partic ular reference to the multi-plane straightedge type, that is, comprising a plurality of straight edges arranged for adjustment in more than one plane.

The primary object of my invention is to provide a simple and novel hand tool or instrument which will be useful to carpenters and other artisans, for such purposes as a straight-edge, a try-square, a bevel-square within a range of 225 degrees or thereabouts, a straight-edge for scribing either one or two sides of a board, and as a so-called base hook for scribing a baseboard at its joint with a base block or a door or window trim, or for similar work.

I have also aimed to provide an instrument of the character described which promotes accuracy, enables the saving of time, and is capable of production at a comparatively low cost.

Other objects and attendant advantages will be appreciated by those skilled in this art as the invention becomes better understood by reference to the following descrip tion when considered in connection with the accompanying drawing, in which,

Figure 1 is a. side VIGWYOf a straight-edge instrument embodying my invention;

Figs. 2 and 3 are sections taken on the lines 2-2 and 3-3 of Fig. 1;

Fig. 4 shows the use of the instrument as a base hook;

Fig. 5 shows the instrument used as a square; and

Fig. 6 shows it used as a bevel for scribing' either one or both sides of a board.

My improved instrument is intended to be used as a hand tool and is of such size as may be conveniently carried in a workmans ocket if desired. The tool may be of any suitable material, but I prefer to make it of aluminum as this is especially well suited for a tool of the character such as I have provided.

The tool or instrument comprises two principal parts, namely, a body 7 and a member 8, each of which is elongated and has all of its longitudinal edges, straight edges. Said body is bifurcated substantially throughout its length providing parallel arms 9 and 10, all longitudinal edges 5, 1923. Serial No. 672,721.

of which are straight edges. The member 8 is substantially square in cross section, is disposed in the opening between the arms 2) and i0, and is pivotally connected by means of a pivot pin 11 to the body 7 at the juncture of said arms. All longitudinal edges of this member are likewise straight edges. Inasmuch as the pivot axis of the member 8 is parallel with the broad flat side of the body 7, said member is adapted to swing in a plane perpendicular to said broad flat side for bringing its straight edges into dilferent angular relations to those of the body 7. Swinging movement of said member is limited in one direction to 90 degrees with respect to the body and in the opposite direction to 135 degrees. To this end, the face 12 of said member abuts against a face 13 on the body for determining the ninety-degree angle, and the face 14 on said member abuts against the face 15 on the body for determining the one hundred thirty-five degree angle. Suitable means is provided for securing the member 8 in any position to which it may be moved, and for this purpose I provide a clamping screw 16 threadingly engaged in the body 7 at right angles to the pivot axis of said member having a knurled head 17 at the exterior of the body adapted to be turned for forcing its opposite end 18 against the rounded end of the member 8 or surface 19 which is concentric with the pivot pin 11. Certain of the sides of the body and member 8 may be channeled longitudinally as shown, simply to reduce Weight.

Many of the uses to which this instrument may be put will be manifest, especially to carpenters and other workmen who have frequent occasions to scribe straight lines. It is however, especially adapted for use as a base hook, as shown in Fig. l. In this figure the body is positioned so that its arms 9 and 10 straddle the baseboard 20 and one of said arms abuts against the adjacent edge 21. of the base block 22, thereby quickly and accurately detern'iining the cutting line, which may be scribed along an edge 23. In this particular case the board 2 -1: is an upright door trim, and the baseboard 20 is adapted to abut against this board. However, it should be understood that this instrmnent may be used under any conditions of like nature where it is desired to scribe a straight cutting line with a complemental edge.

Another useful feature of my instrument is that the straight-edge arms 9 and 10 are adapted to straddle a board for scribing on either or both sides thereof, as will be obvious. As shown in Fig. at, when the baseboard 20 is removed, it may be scribed on both sides along coincident lines 23. And inasmuch as the body 7 and the member 8 are relatively movable to dill'erent angular relation, as shown in Fig. 6, a board may be scribed on one or both sides at any angle within the capacity or range of the present design, which is degrees.

In Fig. 1 have illustrated the use of the instrument a try-square, and it will be manifest that it may be used equally well as a bevel-square. In this regard it will be evident that the member 8 may be secured in any angular position by means of the clamping screw 16.

It is believed that the foregoing conveys a clear understanding of the objects prefaced above, and while I have illustrated but a single working embodiment, it should be understood that various changes might be made in details of construction without departing from the spirit and scope of the invention as expressed in the appended claim, in which- 1 claim:

A straight edge instrument of the character described, comprising a main body member i bifurcated form to provide a head end and spaced parallel arms projecting therefrom arranged to straddle a board or the like, the edges of the arms providing straight edges for scribing purposes, a swingable arm pivotall mounted between the rigid arms at the head end and also providing straight edges for scribing purposes, the head end of the body member liaving a right angle portion on one side thereof to serve as a stop to limit the pivotal movement of the pivoted arm at a position of the arm 90 with respect to the body member and having a bevelportion on the other side of the head end at an angle of approximate 1y 45 with respect to the right angle portion whereby to serve as a stop for the pivoted arm to limit the movement thereof when the same is swung to a position inaiking an angle of approximately 135 with respect to the body member, and n'leans for securing the pivoted arm inany intermediate or limit position of angular adjustment with respect to the body member.

GILBERT LE 1C. 

